Sound-recording apparatus.



T. A. EDISUN.v

SOUND REGORDING APPARYATUS. APPLICATION HLEnfNo'v. 1a, 1903. BBNBWBD JUNE 1o, 1909` 943,664. Patented Dec.21, 1909 ylitnesses K Inventor l f A 0 r ./W A a/m THOMAS A. EDISON, OF LLEW'ELLSZ'N P'.rfil l' -J ERSEY PATENT COMPANY OF GRASSE, NEV JERSEY,

5thereby producing interior-ence.

JERSEY.

Vf JERSEY, ASSIGNOR TO NEW CCEPORATION OF NEXV SOUND--RECGBBING PPAXLATUS.

Application filed November 18, '1963, Sera No. 131,596. Renew-cd (tene To all whom it 'may concern:

Be it known that I, Trroiras Anya Eoison, of Llewellyn Park, Orange, in the county et Essex and State of New Jersey, have in vented certain Improvements in Sounddiecording Apparatus, (Case No. H929 which the following is a descriilfiticn.

Myinvention relates to an improved. tip-- paratus for recording sounds, preferably ot the phonograph type wherein the record is ot varying depth and width, but it maybe utilized in connection with gramophonic apparatus wherein the record is oit' the saine depth and width but of sinuous formation.

The object. of the invention is to eliminate, as far as possible, sympathetic vibrations in sound recording apparatus, whereby the vibrations will be always tore-ed and the recording of extraneous or distorted sound waves will be prevented.

In applications for Letters Patent tiled November 13, 1903, I describe a method and apparatus tor recording sounds, wherein is used a diaphragm whose edges are immersed .in a viscous semiliquid, whereby the diaphragm is 'free to respond to forced vibrations. W ith. an ordinary diaphragm ar ranged in this way, its fundamental tene is so high that it responds sympathetically only to very high notes, and with such tones erally the amplitude is so slight that the recording kni'te is notdisturbed to any great extent. At the same time tones which are in sympathy with the diaphragm are unduly emphasized, so that it is desirable to eradicate even this small disturbance when the perfect quality o't music is to be recorded and reproduced, especially when of instru ments the majority of the notes of which Very high, like a piccolo. l Y

To this end, the invention consists, lirst, in the employment oi al diaphragm of a new type, which While free to respond 'to the sound waves, is dead and non-elastic, so that when o nce lexed to one side of its medial line, it has no tendency ot' itself to vibrate to and tro ,like an elastic body having a fundamental tone ot its own. This is important, because it the diaphragm is elastic it stores up energy when forcibly flexed to either side of; its medial line, leased vibraties in accordance with 'its fundamental tone, which vibrations detract from or add to succeeding sound vibrations, 1lVith my Specification of ieters Patented Dec. 2i, 1909.

io, roos. serial No. 5o1,414.

non-elastic diaphragm the energy stored up by said Ytenure is quickly absorbed as heat and work when the diaphragm is released, and the diaphragm has no tendency in retuning to pi s its medial line because the f gy is consumed during' the return o; the thaphragm to the medial line, 1n this Y0 j bling a dead beat galvanometer.

practically no tendency for it to the said medial line.

rovide composite diaphragm members, which while in themselves elastic and capable of .ilexure or forced vibrations so hindered in their movement as to be practically incapable of comprising any independent vibration, their elasticity' merel` serving to bring them back to their medial position .when flexed.

"The invention consists secondly, in making the soand receives the thrust bit ignite, alsoydead and nonfelastic, and incapable oi v'. )rating et itself, although free to 'follow the forced vibrations ol the diaphragm by means which operate upon sub- `"antially the same principle as the diaphragin.

In order that the invention may be under stood, attention is directed to the accompairing 'drawing' 'forming a part of this st )ecincation and in wlnch Figure i a longitudinal view. on an enlarged scale of a phonographic recording apparatus embodying my invention in its they recording preferred torni; Fig. 2 a plan view ot the saine; and Fig. 3 an enlarged sectional view ot a part ot the diaphragm.

in all oi the above views corresponding parts are represented by the same reference numerals. l

rThe'diaphragm is composed of a pluralit'y ef disks i shown7 preferably formed of mica and of the usual diameter. These disks may all be out the same thickness, buty they prelfeably are t diterent thicknesses, one being l/iOOO of an inch in thickness, the second 2/1000 of an inch in thickness, etc, Under ordinary oonditionsit not desirable to use more than three ot these disks ln the malte-up of the composite diaphragm; The disks are, assembled together with a thin layer oi' afvery viscous permanent semi-- liquid, such as burned rubber, between them and are secured, by a rivet 2 at the center, made preferably of aluminum, and at their In other .alled reed, which connects withk am' aluminum fool; i hel i Vmuch as it is also 'acterizeol by beingl edges by sewing; 3 of silk l' of course, be understood i' be sewecl ogellier by arranged concentricslly be and circumi'ereiiceE bu: Under omini ditions :i single lineol stitch is si l The edges of the composite il ,obrngm immersed in a body of a fous se iiliquid, as l describe in myszii.' implications zipliizi in.S com o c. pcriiieiiiieiill.

i; iiileiiiul fil or .ily zippliee eier lilze siii-luce liereof, elly smiil member reiiflei'ml prziclicnlly iiifzipiible of symplillieie Vibi'nlioiii substrintizilly sel forth.

l coiiipi'isile liliplirmiyiii comprising moor more elastic members zmfl iiiezils zipplieel over lli#y ziiljziceii siii'lqees liereof lor rendering; said iiieniliers practically incapable of svmpzilliel'ic vibration, subslniillinlly lllL coliieposile iliaplnfzigni. tivo or more e iiicmlve und 'zi pci-mw neatly semi-Homie iiiitlerizil clizirziclerizccl by ecb inici-nal friction Yiscosily applied iiibers llie surfaces thereof, rendereil prac l A composite diapliregiii constructed cl'iis .Way has. its capaciy io execuie movemeiis sympzitlieticslly entirely clescroyefl lbe reason tha 'die elasticity of ille disks which under ordinary concliicns would en lire diaphragm lo vibrce to L com prisiiig :me absorbed by fricion develop surfaces of ille disks the viscous liquid and by friction devolo@ ed be@y molecules of tlic said seiiii-liqiii being that While the cliapli tic vibration, execute forced 'vibrli'lioiis les lo Waves, no single impulse has if. 'licinl comprising cause @the diaphragm lo execute f1 F: Vibrations The priately called a, (le

Alfliough my im ed log-,gelber u disks,

c composite clin.m

pliragm is very sensilive re ilisls of dlfcrenctlliele tions so as 'lo accurately .''ollow and urli. :i viscous semithc sound-waves, if flexed ro one side or substantially is set the other of its medial line 'le pressure rcleasecl,' l immediately irri fio ilus form without'parcaling of vibrcicios Secured.- TLo 'lle rmdm .ide of "che rives 'n 'place by s or olher cement and coi-ryu. recorlmife 6 of any. suitable cousuriictioir The sii-called if Whose :l-ont cemented to the fool; miel which i the thrust of 'the recorflcr, is secure rear end by :1 clamp 8 mil same idea as 'ille mprovco. cli-spre sdead and iio-n-elziscie an. incapable of' vibraiiog syriipalletically, This reeel is 'therefore composed of e sc of thin glass' secions prc'erably of ve A thickness, separated by thin layers of s -..scous pe 'marient semiliquida like burned rubber, the Whole being Wound by s sill: thread 9. Instead of securing lie rcerl sections ocomposie 'wo or more rif 'the cellier w liaphropm composed of l. dislgs secured. togetl'ier :it i viscous semi-liquid betweenl forth.

l brews i lli disk fr composite diaphragm composed ol islit" cl. disks ,riveted iogctlier :it the i sewcd al; 'their edges with a Yvissemi-l` iiicl between che disks, substanl cous molly as s 9. A composite reeel for receiving the "'clirust ci :i phonogrspbc recorder comprising sin elastic member and 'means for rendering said member practically'incapable of sy1n pillielic vi.briilioirl subsfauitinlly is sel: forth,

gether by ai sill: tl'irezicl7 a series of small l0. i?. cemjfiosicc reed rcceivuig the till-ust rubber bands may be emo @veel willi il )li recorders composed of :l pluzwes with viscous semi hein, subsliziiiinlly als set results. lt will of course i er miierizil than the reed may be mafie of 1 cl 1S charl glass, such as thm splints or bami oe. I

With the arrangementdescribe@ l eliniil composite reed {goirecoiving the nate all vibrations olhcr lliari vlmli l l; Y oliouogrzipli recorders composed oil those are forced so that :i record forli' e e i' lem/'es ol .f'ziiying thickness with iseous seiiii-liqiiid between licm, substzinilly as .sely forth. l?, reed for receiving` l'lie thrust ol l' Vnogrzzpli recorders composed of :i series y -ziss leaves willi o `viscous semi-liquid bcieeii lli-cirx9 subsisuliclly sei. forth.

fr composi'le reed. for receiving the liris; of phonograph recorders composed of coini'iosed solely graphie represeiilziioiis of tl sound-waves y themselves recorded Wili :ibsoliile :icciiirzicy r iiidffree of ex'trmeous dislurbciices and di;v i tortion. Having' now describe@ my iiiiveiii l I claim as new and desire 'to secure l ters Riten@ is as follows: l 

